Known anesthesia and/or respirator systems frequently suffer from a disadvantage, in that they are technically complicated and therefore become quite expensive. Of course, simpler and/or cheaper systems do exist, but in many cases these systems are then considered to be unreliable or just cannot fulfill the functions to which they are normally required to perform. Furthermore, there is presently unavailable an apparatus which includes simple means for the reliable measurement of the quantity of liquid being supplied for gasification or evaporation, and which controls the supply of such liquid to a gasification chamber through one or more metering valves.